This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2001-200177, filed Jun. 29, 2001, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a connector for connecting flexible printed circuit boards, a head actuator provided with the connector, and a disk drive.
2. Description of the Related Art
In general, a disk drive such as a magnetic disk drive comprises magnetic disks, a spindle motor for supporting and rotating the magnetic disks, a head actuator supporting magnetic heads, a voice coil motor for driving the head actuator, a substrate unit, etc, which are housed in a casing.
The head actuator includes a bearing portion attached to the casing and a plurality of arms extending from the bearing portion. A magnetic head is mounted on each arm by means of a suspension. The substrate unit includes a main flexible printed circuit board (hereinafter referred to as main FPC), the distal end portion of which extends close to the bearing portion. Each magnetic head is connected to one end of a relay flexible printed circuit board (hereinafter referred to as relay FPC) on each arm, and the other end portion of the relay FPC is connected to the main FPC. Thus, each magnetic head is connected electrically to the substrate unit through the relay and main FPC""s and controlled by means of the substrate unit.
In the case where the printed circuit boards are connected electrically to each other in this manner, each printed circuit board is provided with connecting pads, a pre-tinning layer is formed on each connecting pad, and the pads are opposed to one another. In this state, the pre-tinning layer is heated from the base-layer side of one of the printed circuit boards. By doing this, the pre-tinning layer is melted to connect the pads electrically and mechanically.
Possibly, the relay and main FPC""s may be connected by contact bonding. In the magnetic disk drive, however, the connected portion between the relay and main FPC""s moves as the head actuator rocks, and is subjected to vibration and shock. Accordingly, soldering is widely used to improve the reliability of connection.
In conventional assembly processes for a magnetic disk drive, soldering the FPC""s is carried out in a clean room. However, the soldering operation includes a process for melting solder by means of a soldering iron. In this process, outgassing from a flux or the like in the solder may generate, possibly contaminating the atmosphere in the clean room and exerting a bad influence upon other components.
Further, soldering the relay and main FPC""s involves operation for soldering very fine connecting pads, so that the reliability of the soldering is easily influenced by workmanship.
Furthermore, repairing the head actuator requires resoldering after the solder on the connecting portions is removed. Thus, repairs are troublesome and their achievement level easily lowers. In addition, an MR element is used for the magnetic head being in current use so that the magnetic head of this type is very weak against static electricity. Therefore, in assembly for a head actuator and magnetic disk drive provided with the same, it is necessary to take measures against electrostatic breakdown to prevent a large current from flowing into the magnetic head from outside.
The present invention has been achieved in consideration of these circumstances, and its object is to provide a connector for flexible printed circuit boards, capable of easily securely connecting flexible printed circuit boards, a head actuator provided with the same, and a disk drive.
In order to achieve the above object, a connector for flexible printed circuit boards according to an aspect of the invention is a connector for electrically connecting a pair of first flexible printed circuit boards, fixed individually on the respective surfaces of two arms spaced and opposed to each other and each extending from a distal end portion of each arm to a proximal end portion thereof, and a second flexible printed circuit board extending from any other portion than the arms toward the proximal end portions. The connector comprises: a female connector formed of the first flexible printed circuit boards; and a male connector provided at the second flexible printed circuit board.
The female connector includes a pair of connecting portions formed on respective proximal-side end portions of the first flexible printed circuit boards and opposed to each other across a given space, each of the connecting portions having first contacts formed by exposing a part of a conductor pattern of the first flexible printed circuit board, a plurality of short-circuit contacts and a short-circuit piece which contacts with the plurality of short-circuit contacts so as to turn the conductor pattern into a closed loop.
The male connector includes a projection and a pressing portion which are configured to be fitted between the connecting portions of the female connector, second contacts provided on the projection and connected to a conductor pattern of the second flexible printed circuit board, the second contacts being arranged so as to contact with the first contacts when the projection is fitted between the connecting portions, and the pressing portion being configured to press and detach the short-circuit piece from the short-circuit contacts and release the closed loop when the pressing portions are fitted between the connecting portions.
According to the connector for flexible printed circuit boards constructed in this manner, the first flexible printed circuit boards and second flexible printed circuit boards can be connected electrically to each other by only inserting and fitting the projections and pressing portions of the male connector that is attached to the second flexible printed circuit boards into the spaces between the connecting portions of the female connectors. Thus, connecting the first and second flexible printed circuit boards requires no soldering, and therefore, never contaminates the atmosphere in a clean room. Further, no veteran skill is needed, and variation in workmanship can be lowered.
In addition, since the female connectors are constructed by opposing the connecting portions of the first flexible printed circuit boards that are attached to the arms, no dedicated housings for the connectors are needed, so that the construction can be simplified.
The connecting portion provided on the first flexible printed circuit board of each arm has the short-circuit contacts and short-circuit piece that short-circuits the same, and thus the arm itself comprises a short-circuit mechanism for preventing electrostatic breakdown from occurring thereon. Therefore, even in the state that the arm has not been assembled and remains intact, it is possible to prevent electrostatic breakdown from occurring on electronic components connected to the first flexible printed circuit board.
Furthermore, when the male connector is connected to the female connectors, being linked with this connection, the short-circuit carried out by the short-circuit piece is released. Thus the first and second main flexible printed circuit boards can be electrically connected to each other. When the male connector is detached from the female connectors, a closed loop is formed in the first flexible printed circuit boards by means of each short-circuit piece again, thereby firmly preventing electrostatic breakdown from occurring on the electronic components.
Consequently, by inserting and extracting the male connector in and from the female connector, a function of preventing electrostatic breakdown can be stopped or resumed easily. Thus, the connection between the first and second flexible printed circuit boards can be facilitated, moreover, repairs such as replacing the electronic components can be carried out easily.
A head actuator according to another aspect of the invention comprises: a bearing portion; two arms each having a proximal end portion attached to the bearing portion, and a distal end portion supporting a head, extending from the bearing portion, the arms being opposed to each other across a given space; first flexible printed circuit boards fixed individually on the respective arms, connected electrically to the respective heads, and extending from the heads to the proximal end portions of the arms; a second flexible printed circuit board connected to the first flexible printed circuit boards; and a male connector attached to the second flexible printed circuit board.
Each of the first flexible printed circuit boards includes a connecting portion provided at the proximal end portion of the arm and having first contacts formed by exposing a part of a conductor pattern, a plurality of short-circuit contacts, and a short-circuit piece which contacts with the plurality of short-circuit contacts so as to turn the conductor pattern into a closed loop.
The respective connecting portions on the two arms are opposed to each other across a given space to constitute a female connector.
The male connector includes a projection and a pressing portions which are configured to be fitted between the connecting portions of the female connector, and second contacts provided on the projection and connected to a conductor pattern of the second flexible printed circuit board, the second contacts being arranged so as to contact with the first contacts when the projection is fitted between the connecting portions, and the pressing portions being arranged so as to press and detach the short-circuit piece from the short-circuit contacts, and release the closed loop when the pressing portions are fitted between the connecting portions.
A disk drive according to still another aspect of the invention comprises a disk; a head configured to write in and retrieving information from the disk; a head actuator supporting the head for movement with respect to the disk; a substrate unit configured to input and output signals with respect to the head; a main flexible printed circuit board extending from the substrate unit and connected to the head actuator; and a male connector attached to the main flexible printed circuit board.
The head actuator includes a bearing portion; two arms each having a proximal end portion attached to the bearing portion, and a distal end portion supporting the head, extending from the bearing portion, the arms being opposed to each other across a given space; and relay flexible printed circuit boards fixed individually on the respective arms, connected electrically to the respective heads, and extending from the heads to the proximal end portions of the arms.
Each of the relay flexible printed circuit boards includes a connecting portion provided at the proximal end portion of the arm and having first contacts formed by exposing a part of a conductor pattern, a plurality of short-circuit contacts and a short-circuit piece which contacts with the plurality of short-circuit contacts so as to turn the conductor pattern into a closed loop, the connecting portions being opposed to each other across a given space to constitute a female connector.
The male connector includes a projection and a pressing portions which are configured to be fitted detachably in and from the female connector, and second contacts exposed on the projection and connected to a conductor pattern of the main flexible printed circuit board.
The first contacts of the female connectors and the second contacts of the male connector are pressed to each other by fitting the projection and pressing portion of the male connector into the connecting portions of the female connectors, so that the relay flexible printed circuit board and the main flexible printed circuit board are electrically connected to each other, and the short-circuit piece is pressed by means of the pressing portion to come apart from the short-circuit contacts, thereby releasing the closed loop.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.